Disclosed herein are methods for digital document processing, and in particular to such methods that modifies on demand special information in a raster image, as well as corresponding apparatus and computer-readable medium.
A raster image processor (RIP) provides output data in a format that is suitable for rendering by an output device such as a printer. One suitable format is raw, binary dot patterns forming a bitmap. Rendering by the output device may include printing by a printer, and displaying on a screen. The raster image processor receives input of one or more page descriptions. The page descriptions includes information about fonts, graphics, and the like that describe the appearance of each page. The page descriptions may be in a high level language or even another bitmap of higher or lower resolution than the output device. Some examples of high level page description languages are PostScript (PS), Portable Document Format (PDF) and Extensible Markup Language (XML) Paper Specification (XPS). The raster image processor may be implemented as software, firmware, and/or hardware. Typically, the raster image processor resides in a digital front end (DFE). The raster image processor performs raster image processing (RIPping). Raster image processing is the process of translating the page descriptions into a RIPped image or into a bitmap for output by the output device like desktop printer. Raster formats include: TIFF (Tagged-Image File Format),PSD (Photoshop Document),EPS (Encapsulated PostScript),JPEG (Joint Photographic Experts Group),PNG (Portable Network Graphics),GIF (Graphics Interchange Format),BMP (Windows Bitmap),EMF (Enhanced MetaFile), EPS (Encapsulated PostScript),PDF (Portable Document Format),PS (PostScript),PGM (Portable Gray Map), PPM (portable pixel map),PBM (portable bit map),EXIF (Exchangeable image file format),RAW (raw image format),SVG (Scalable Vector Graphics), CGM (Computer Graphics Metafile),XBM (X BitMap),ILBM (InterLeaved BitMap),WMP (Windows Media Photo),WBMP (Wireless Bit-Map or Wireless Application Protocol Bitmap Format),PNM (Portable Bitmap).
Printed documents often require additional information in the form of symbolic encodings or marks to provide additional data about the document that may or may not have anything to do with the content of the document. For example, the information can be tracking data, workflow information such as creator and device used for creating the document, and/or even security designations. This data might even be instructions for further processing such as finishing, packing, or routing that need to be read further down line in the process.
As the number of applications grows so do the number of additional marks that need to be added to the output image of the document to be printed. These marks can become distracting or even unattractive. Current attempts to solve this growing problem have included data compression in the symbols used or different toners for marking that may be harder to see by the normal eye. One major drawback that these approaches have is they don't have the capability to change the special information on demand. An example would be a document which is marked with printing tracking information that is subsequently changed. In the current print process it is difficult to alter the page content so such a document would have to be processed offline to accommodate the post marking changes.